– PSMA-11, also known as DKFZ-?PSMA-?11, HBED-CC-PSMA or Psma-hbed-CC, is a ligand to make gallium Ga 68-labeled PSMA-11, which has potential use as a tracer for PSMA-expressing tumors during positron emission tomography (PET). Upon intravenous administration of gallium Ga 68-labeled PSMA-11, the Glu-urea-Lys(Ahx) moiety targets and binds to PSMA-expressing tumor cells. Upon internalization, PSMA-expressing tumor cells can be detected during PET imaging. PSMA, a tumor-associated antigen and type II transmembrane protein, is expressed on the membrane of prostatic epithelial cells and overexpressed on prostate tumor cells